Process of making cyanids.



maimed January 31', 1905.

Prvrnixrr OF CE.

Jo'sEPH TGHERNIAU, OF FREIBURG, GERMANY.

PROCESS OF MAKING-ICYANIDS.

SPECIFICATION forming part of Letters Patent No. 781,472, dated January 31, 1905.

v I Application filed August 8, 1904. Serial No. 220,043. I

v To all whom it may concern:

ing a sulfocyanid and absorbing the hydrogen cyanid by a heated alkali' carbonate or hydroxid.

My present invention relates to an improvement in the use of alkali hydroxid as an absorbent for the hydrogen cyanid.

I now find that in order, to obtain a highgrade colorless cyanid the alkali hydroxid must be heated to a temperature below its melting-point, but above that at which the water generated by the reaction. is completely vaporized. Thehydroxid should be finely divided, and although the temperature must at first be below that at which the hydroxid melts it may be raised gradually as the latter becomes converted into cyanid. For instance, when caustic soda is used. (best in thin slices or as powder) the temperature may be 200 Centigrade to begin with. Some fifty to sixty per cent. of the caustic soda will become cyanid at this temperature. To complete the conversion, the temperature may be raised to 300 centigrade, which, may be done without danger, as the melting-point of the mass rises considerably as the formation of cyanid proceeds. Instead of raising the temperature the massmay be broken up or ground (best in the absorption apparatus itself) and the temperature maintained at 200 centigrade until the soda is saturated. 'By working in this man- 4 nor and using two orthree absorption apparatus in series the soda iscompletely saturated and the hydrogen cyanid fully absorbed.

completely vaporized, substantially as described.

2. In the manufacture of cyanids by absorbing hydrogen cyanid by caustic soda, heating the latter first ata temperature ofabout 200 centigrade and then at about 300 centigrade, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOSEPH TGHERNIAC.

Witnesses:

LUDWIG GRINBUL, BENJAMIN F. LIEFELD. 

